Improved scaffold



l tlntrll faire ,f GEORGE ADMspJR., OEALEXANDER, NEW YORK. J "Le-raft maar No." 89,840, dated May 11,1869. d

'IMPRovED scAFFoLD.

The Schedule referred to in these Letters Patent and making part of the same.

To all whom 'it mag/concern: v

Be it known that I, GEQRGE'ADAMS, Jr., oAlexander,in the county of Genesee, and State ofNew York, have invented certain newand useful Improvements in Scafiolds; and I do hereby declarethat the following is a full and-exact description! thereof, reference being had to the accompanyingdrawings, making 4part of this specification. l

. My improvements` relate toa scaifold designed -more especially for builders use, which is raised .or lowered by the workmen thereon. In the drawings` Figure I Yis a side elevation lof my improved apparatus. ,1"1` d Figure II is,`a vertical cross-section, Lwith ,some of the parts removed. l.

Figure III is a view of the brake-lever, pawl, and

ratchet-wvheel detached.

4 Figures IV, V, and VI, are` an enlarged edge view, d a side view, and plan of the `hoisting-pulley attop of the standards.

Figures VII and' VIII are` enlarged sectional detached views, showing thepawl-hook, its connections, and a cross-section of l one of the standards.

yFigure IXis aplanof the brake `and hoisting-gearing. f d r Like letters, refer to Alike parts in each of the figures. j A is the platform, forming the scaffold; B B, two guide-supporting standards, one at each end of the d l platform, provided with suitable braces, c c, to maine is a bail at each end of the platform, having wings `or guide-irons, f, Fig. VIII, near its upper end, which overlap the edges ofthe standards similar to the irons d, and serveto steady the platform. l

I These bails connect at their upper yends with hooks orpawls, g, asinost clearly shown i/n Fig. VII.

To these hooks, a`tlso,*attach` the hoisting-ropes h, which pass around pulleys I at theftop of the standards, and thence downward through the platform and aroundja pulley, j, to a windlass, K, Fig. II, arranged underneath the same.` Y The standafdsB, o`n their inner face, are formed with recesses or ratchets., b, in which the hooks g engage in supporting the platform; ,l

'Ihese recesses or shoulders maybe provided with staples, b', in which the hooks engage, ii' required. j

At one vedge of the platforrmrnounted at the' top `ot' suitable standards, N, is la crank-shaft, lt, provided with a winch, l, at each end,aud having mounted.

.thereon a chain-pinion, fm, a ratchet-wheel, n, and friction er brake-wheel o. f

`From the pinion m a chain, `p, descends` around a A brake-strap, a, of leather, or other suitable terial, isattached to a cross-rod, connecting the arms r, and passes around andv over the wheel o,jand attaches to the end of lever L. i n v To an arm, P, extending from the opposite side of the standard N, is hinged the end of a pawl, q, formed with one or 'more teeth to engage with the ratchets of the wheel n. f The end of thispawl rests on a pin at the upper end of the brake-lever, and keeps the brake from pressing the wheel.

The brake is applied to the wheel o by depressing the brake-lever, the endvr of which also serves to raise and disengage the pawl from the ratchet-wheel.

A rope, s, attaches to the ends of each of thepawlhooks g, from whence it descends through the plat- Y form and connects with one end of the angle-levert. l From the other arms of these levers, ropes s connect withtwo arms u, attached .tofa rock-shaft, o.

At one end of this rock-shaft is an arm, w, from the end of which a pull-rod, w', passes up through the platform, where it isprovided with a suitable handle for operating it, as shownin Fig. I. y

If desired, a small chain and crank-wheel, x, ands crank-wheel may be arranged intermediate the two wheels fm, Q, on the same shaft, the whel a: engaging with the chain p. Y

These wheels x x have each a pitman, y, attached thereto, thefree ends of which reciprocate in suitable guides, and are provided with foot-rests y', so as to be operated'by the feet, while the `hands operate the y Winches l. Y

The pulley-blocks I are constructed with hooks fl i,

whichpiit overthe ends of the standards, as shown in` Figs. IV 4and VI, being jretained in place by pinsz" passing through the standards, as clearly shown.

The operation of my improved apparatus, constructed as before described, is as follows:

\ The platform and standards A B being connected and arranged at the place required, and the latterr properly braced, the Workmen mount` the platform, which rests on the ground, and/by turning the cranks l, (the foot-device being operated or not, as desired,)

the ropes h are woundyupon the windlass K, which d elevates the platform. v v n The connection ofthe hoisting-rope with the hooks gis such as that strain ony the rope in raising the platform tends to press the hooks against `the ratchets in the standards, over which they slide as the- 'platform ascends, but which' engage with the same when the Amotion ceases, andl securely retain the yplatform in' place, the pawl. q also engaging with the ratchet- Wheel n, forming a double fastening.

When the platform is required .to be lowered, it is first slightly elevated, so as to disconnect the hooks g. Then, by pulling on the rod, the hooks g are drawn away from contact With the ratchets of the standards, the pawl q preventing the descent of the platform.

By applying Vthe brake L a, as before described, the pawl gris disengaged, and the platform easily and gradually lowered to the required point, when, by releasing the pull-rod, the hooks g again engage with the standards, and the pawl with the ratchet-Wheel n.

For elevating the scaffold to the top of high buildings7 the standards may be dispensed with, the pulleyblocks I beingr fastened to the top of the building, Where the scaffold is elevated and lowered,as before described, (the hook-disconnecting device not being required,) and retained at any point by the pawl 'q and ratchet-wheel vn.

In such case I employ adjustable guard-arms D D, arranged and secured transversely of the platform by guides z, with friction-rollers z, at their ends, which may be adj usted, so as to project a greater or less distance from the edge of the platform.

These arms serve to keep the platform away from contact with the side of the building, the friction- Wheels traversing up and down the same as the scaffold israised and lowered.

The standards B, when they are used, perform this function, and render the use of such lguard-arms unnecessary.

In transporting the scaffold, the standards B may be disconnected from the platform, so that the Whole apparatus can be folded compactly together.

The advantages of my improvements for painters use, as well as for builders generally, and also for other purposes, Where a scaffold is required, -are obvious, ladders, and the' labor and expense of material for building, and adj nsting the height of the scaffold, being avoided. v

What I claim as my invention, and desire to secure by Letters Patent, is-

1. The standards B, platform A, bails c, pawl-hooks g, ratchets b, and hoisting-cable h, when arranged and combined to operate substantially as herein set forth.

2. The crank Z and chain-pinion m, supported above the platform, in combination with the Windlass K and chain-wheel Q, below the platform and the connecting chain, guide-pulleys j, and cable h, arranged to operate and for the purpose described.

3. The arrangement of the crank and chain-wheels x and x', pitmen y y, and foot-rests y y', as described.

4. The combination and arrangement ofthe brakelever and strap L a, with pawl rand ratchet-wheels q n, as and for the purpose specilied.

5. The combination of the ropes s, angle-levers t, rope s', arms u w, and pull-rod w, with the hook-pawls g, for disengaging the latter, as set forth 6. The combination and arrangement of the ratchetstandards B, braces c, and pulleys I, with the platform A, supporting-pawl hooks y, and hoistingfrope h, substantially as and for the purpose set forth. v

7. The pulley I, provided with hooks c' and eye i, constructed in the mannerl and for the purpose described.

8. The adjustable guard-arms D, provided with friction-rollers z, arranged and operating as set forth.

GEO. ADAMS, JB.

Witnesses:

` JAY HYATT,

JN0. J. BONNER. 

